Wet Soil on Mars: A Dissertation Word Cloud

Most of my graduate school classmates (at MIT’s science writing program) went on to pursue freelance writing careers. Not Selby Cull. The inimitable Ms. Cull–a planetary geologist with the impressive ability to convince her skeptical classmates that rocks are, in fact, “sexy”–decided to pursue her PhD.

Selby recently defended her dissertation, a development I discovered when I came across an interesting image on Facebook. Selby, had, in fact, turned her dissertation into a large word cloud.

I am reprinting the graphic below (with Selby’s permission), but first, some context. In Selby’s own words: “NASA’s Phoenix mission landed on the northern plains of Mars in May 2008, and I devoted my dissertation to tracking the water cycle at the landing site. I found that the site is covered by a thick layer of carbon dioxide ice for half of the year, and covered by water frost for almost 85% of the year. Most interestingly, I found that the water frost interacts with salt in the soil to form thin films of liquid water — the soil at the Phoenix landing site is wet!”